Utility vehicles are widely used in many industries. Typically, a utility vehicle such as a farming tractor is used along with a trailer which carries out a farming function. As used herein, a "utility vehicle" is a tractor or the like and optionally used with a trailer or the like. Many different types of trailers can be used with a farming tractor as is well known in the art. The operation of a farming tractor and trailer combination usually has at least one person to operate the tractor. For many operations or tasks, additional people are needed.
It is desirable to operate a utility vehicle in order to minimize operating costs. This is particularly important in farming because of the high costs associated with the use of utility vehicles. While there are many approaches available for optimizing costs, there are two important approaches for optimizing driving parameters relative to the instant invention. Generally, the terms "optimum", "optimization" and "optimizing" refer to obtaining operating conditions for maintaining a predetermined minimum or maximum of a parameter such as fuel consumption, work output per unit time or the like. Other parameters or measurable quantities can be used to evaluate a selected parameter. The operating conditions are usually defined by ranges to avoid excessive demands for maintaining an optimum operating status.
One important approach for optimizing driving parameters is to focus on fuel costs. Under such circumstances, the selection of the operating gear and the engine speed for the farming tractor are coordinated so that fuel consumption is minimized for the engine speed or gear selected by the operator. In such operation, if the operator or driver selects a particular operating transmission gear or gear ratio, the speed of the engine is selected by the use of the throttle or fuel pedal in order to minimize fuel consumption for the selected operating transmission gear. If, however, the operator operates the throttle so as to obtain a particular engine speed, then the operator changes the gear ratio in order to provide fuel economy for the selected engine speed. Generally, ranges are used for parameters. Thus, the engine speed need only be within a certain range to fulfill the goal of optimum economy.
British Patent No. 1,330,350 discloses a system for fuel efficiency for a vehicle. U.S. Pat. No. 4,439,158 discloses a system for providing an indicator to inform an operator of an appropriate gear ratio for a given engine speed in order to economize fuel. U.S. Pat. No. 4,459,671 also discloses a system for fuel management control for a vehicle. These patents are incorporated herein by reference. Numerous other prior art references address this problem and show the degree of sophistication of skilled individuals in the art.
Fuel economy calculations for a vehicle such as a utility vehicle preferably utilizes actual performance data for the vehicle. Such data is accumulated by measurements being carried out for the vehicle under different operating conditions. The data can be stored in a conventional computer memory and a conventional computer is used to establish the correlation between gear ratio and engine speed to establish fuel economy.
Another important operating condition is to maximize the production or work output of the utility vehicle per unit time. As used herein, the "maximum work output per unit time" refers to maximizing the work or task of the utility vehicle per unit time. The work or task can be collecting a product, or treating the soil or the like. This is particularly important when the work or task is "labor intensive". That is, the work requires support personnel. In some cases, the task of the utility vehicle may be to cut and collect wheat while in another operation the utility vehicle may be to aerate the soil. For some operations or tasks, the combination of the farming tractor and farming trailer requires the help of additional workers and the total cost per unit time for the task can be substantially large due to the labor costs.
Generally, a high operating cost per unit time for a task creates an incentive to minimize the operating time by maximizing the output per unit time. It is convenient to measure the output per unit time in terms of the engine torque which is referred to herein as the "engine power output". The loading of the engine or the transmission system producing the engine power output can be measured by measuring the rotational speed at the output of the transmission system. As in the case of fuel economy, data must be collected in order to establish the relationship between the transmission loading or speed and engine speed relative to output per unit time. Some of the data can be based on theoretical calculations and other data ca be obtained empirically. The computations for optimization can be carried out using a conventional computer. U.S. Pat. No. 4,485,443 discloses a system for controlling the torque in a fluid-operated friction coupling clutch. U.S. Pat. No. 4,541,052 discloses a vehicle power output regulation control system. These patents are incorporated herein by reference.
The references disclosed herein are indicative of the interest in the prior art of optimizing the operation of vehicles. While these references provide partial solutions, none of these references provides a broad solution for optimizing a utility vehicle under different important operating conditions. Furthermore, the prior art does not address the optimization of output per unit time. Generally, the references disclosed herein have substantial different operating components so that combinations of systems are not realizable. Furthermore, even if the references were combined, the instant invention would not be produced.